Ask PYS: Power

Lithium vs. Firefly Carbon Foam Batteries, on Jun 15, 2017 asked:

We currently have a 440Ah lead/acid house battery bank and a lead/acid starting battery that I want to upgrade to a more maintenance free battery type. Can you provide an opinion regarding the advantages/disadvantages of lithium ion vs carbon foam batteries in the marine setting? Since I am looking long term and planning to keep the boat, a higher initial cost is acceptable if the benefits are significant. - Pete

I’d suggest the Lithium makes sense over Firefly if: 

  • You need a battery bank that offers the most energy density for available volume and weight
  • You plan on using your battery bank regularly, i.e. thousands of cycles, for instance cruising offshore and cycling the batteries every day for 5-7 years
  • You are OK with the costs of upgrading your alternator, charger, solar controllers to lithium compatible devices

 All those benefits are potentially offset by large upfront capital costs.  Otherwise, I’d go with Firefly AGM.  – Jeff